Ppal99 Dissecting Usmle Step 1,2,3 Amino Acids

Front 1

what are the sources of Energy?

Back 1

• Proteins
• Fats
• Sugars

Front 2

which one is easiest to mobilize?

Back 2

sugars

Front 3

describe the properties of a charged molecule ie. amino group (-NH4 +)

Back 3

Amino Group (-NH4 +): Charged, more soluble, attracted to water

Front 4

describe the properties of a uncharged molecule ie. acid group (-COOH)

Back 4

Acid Group (-COOH): Uncharged, crosses membranes, reflection coefficient closer to zero, more
bioavailable

Front 5

Buffers:
what is the intracellular buffer?, extracellular buffer and the best buffer?

Back 5

• Intracellular: Protein (RBC's=hemoglobin)
• Extracellular: Bicarbonate
• Best Buffer: Histidine (pK = 6.0, sidechain closest to pH=7.4)

Front 6

what is an Amino acids:

Back 6

have an NH3+ and a COOH

Front 7

Proline: where is it more abundant?

Back 7

imino acid ⇨ think kinks, twists, bends, turns (Ex: GI, hair, blood vessels)

Front 8

Dissociate

Back 8

=> take H + away!

Front 9

Bioavailable

Back 9

=> neutral, can cross membranes, fat soluble

Front 10

Soluble

Back 10

=>charged or polar, water soluble (Sulphur, Oxygen, Nitrogen)

Front 11

Acids

Back 11

pKa<7, likes to give up hydrogen ions, dissociates early

Front 12

Base:

Back 12

pKa>7, likes to accept hydrogen ions, dissociates late

Front 13

pKa 1-3

Back 13

Strong acid

Front 14

pKa 4-7

Back 14

Weak acid:

Front 15

pKa 7-9

Back 15

Weak base:

Front 16

pKa 10-14

Back 16

Strong base:

Front 17

pKa of 4-9

Back 17

can be a weak acid or weak base

Front 18

what happens when an acid dissociate:

Back 18

gains negative charge, more soluble, less bioavailable

Front 19

what happens when a bases dissociate:

Back 19

loses a positive charge, less soluble, more bioavailable

Front 20

Henderson-Hasselbach Equation

Back 20

pH= pK -log Base/ Acid

Front 21

what does it mean when pH= pK

Back 21

Half acid and half base
• 50% dissociated
• 50% soluble
• 50% bioavailable
• 50% reflection coefficient close to 1
• 50% reflection coefficient close to 0
• 50% crosses BBB (bioavailable)
• 50% metabolized by liver (bioavailable)

Front 22

pH: pK+2
Dissociated = Water Soluble:
Bioavailable=Fat Soluble:
for both acid/ base

pK+2 99% 1%

Back 22

Dissociated = Water Soluble/
Bioavailable=Fat Soluble
99%/1% (acid), 1%/99%

Front 23

pH: pK. + 1
Dissociated = Water Soluble:
Bioavailable=Fat Soluble:

Back 23

Dissociated = Water Soluble/
Bioavailable=Fat Soluble
90%/10% (acid), 10%/90% (base)

Front 24

pH:pK
Dissociated = Water Soluble:
Bioavailable=Fat Soluble:

Back 24

Dissociated = Water Soluble:
Bioavailable=Fat Soluble

Front 25

pH: pK. - 1
Dissociated = Water Soluble:
Bioavailable=Fat Soluble:

Back 25

Dissociated = Water Soluble/
Bioavailable=Fat Soluble
50% "Best Buffer" 50%

Front 26

pH: pK.- 2
Dissociated = Water Soluble:
Bioavailable=Fat Soluble:

Back 26

Dissociated = Water Soluble/
Bioavailable=Fat Soluble
1%/99% (acid), base 99%/1% (base)

Front 27

Rules to keep molecules neutral (bioavailable):

Back 27

• To absorb more acid, place in a stronger acid
• To absorb more base, place in a stronger base

Front 28

Common Acids

Back 28

NH4Cl, ASA, Barbiturates, Myoglobin, Juice, Coke

Front 29

Common Bases

Back 29

Bicarb, Amphetamines, Baking soda, Activated charcoal, Milk

Front 30

what are the anti-inflammatories?

Back 30

Acetaminophen
NSAIDs: COX inhibitors
COX-2 Inhibitors

Front 31

Acetaminophen: MOA, SE and toxicity tx

Back 31

works at hypothalamus to decrease temp
• Liver toxicity: microsteatosis (highest levels in first 4 hours)
• Tx: N-acetylcystirte (absorbs free radicals)

Front 32

NSAIDs: SE and what are the two types of NSAIDs and location

Back 32

COX inhibitors => GI bleeding, interstitial nephritis
COX-1: on gut tissue
COX-2: on endothelial tissue

Front 33

what are the COX-1 inhibitors

Back 33

Indomethacin
Phenylbutazone
Ketorolac
Baclofen
Cyclobenzaprine
Naproxen
Ibuprofen
asa

Front 34

Indomethacin

Back 34

most potent => RTA, closes PDA, tx gout

Front 35

Phenylbutazone

Back 35

2nd most potent

Front 36

Ketorolac

Back 36

morphine-like, use w / drug addicts

Front 37

Baclofen

Back 37

tx back pain (GABA-ergic effect)

Front 38

Cyclobenzaprine

Back 38

anti-cholinergic effects (hot, dry skill)

Front 39

Naproxen

Back 39

tx dysmenorrhea

Front 40

Ibuprofen

Back 40

OTG

Front 41

asa

Back 41

acetylates COX-1/2 irreversibly=> most effective platelet inhibitor

Front 42

why can we use aspirin in asthma patients

Back 42

induces asthma sx because ⇧LT by blocking COX.

Front 43

don't use aspirin w/ hyperthyroid pts?

Back 43

displaces T4 from TBG

Front 44

why can't gout patients use aspirin?

Back 44

⇩urate excretion.

Front 45

COX-2 Inhibitors advantage

Back 45

decreased GI irritation

Front 46

what are the cox 2 inhibitors

Back 46

• Celecoxib
• Rofecoxib
• Valdecoxib
• Meloxicam

Front 47

Platelet Haptens:

Back 47

• Quinidine}
• ASA (>81mg}
• Heparin

Front 48

which cox 2 inhibitor has sulfur?

Back 48

Celecoxib

Front 49

which cox 2 inhibitor was taken of the maket due to stroke increase?

Back 49

Rofecoxib

Front 50

which cox 2 inhibitor does not have sulfur?

Back 50

Valdecoxib

Front 51

ASA Toxicity

Back 51

1) Resp Alkalosis (⇧RR)
2) Metabolic Acidosis (uncouples OP)
3) Mixed Acidosis (⇧GABA)

Front 52

Sulfur Side Effects: CI

Back 52

don't give to pregnant women

Front 53

Sulfur Side Effects

Back 53

Anaphylaxis
Rash
Interstitial nephritis
Hemolytic anemia
Met-Hemoglobin
Displaces stuff off of albumin Kidney stones

Front 54

what are the Street Drugs: Uppers? and what effect do they have on the eyes?

Back 54

dilated pupils
PCP
LSD
Amphetamines
Nicotine
Ecstasy

Front 55

PCP "angel dust":

Back 55

blocks NMDAr =>powerfully violent, nystagmus, ⇧CPK, ⇧SGOP

Front 56

LSD "acid, trips":

Back 56

5-HT agonist => laid back=> colorful hallucinating

Front 57

Amphetamines "speed, ecstasy, ice=smoked":

Back 57

hyperactivity, vertical nystagmus

Front 58

Nicotine

Back 58

⇩DA reuptake =>agitation, cotinine metabolites in urine
(Tx: Bupropion)

Front 59

Ecstasy

Back 59

very thirsty

Front 60

Cocaine

Back 60

"coke, snow, crack=smoked": ⇩DA reuptake
o Condescending, grandiose, big pupils, formication, HTN, ⇧TPR
Fetus: ⇩limbs, VSD, brain bleed, placenta abruptio

Front 61

Cocaine Chest Pressure Tx:

Back 61

1) BZ (⇩HR/BP)
2) Nitrate» (⇩vasospasm)
3) Aspirin (⇩thrombi)

Front 62

Cocaine HTN Tx:

Back 62

1) Lorazepam (anxiolytic)
2) Phentolamine (⇩BP)
3) Avoid β-blockers

Front 63

Opiod Withdrawal Tx:
neonates
adults

Back 63

Neonates: Paregori"
Adults: Clonidine /Methadone

Front 64

Cocaine Rhabdomyolysis Tx:

Back 64

1) IVF
2) Bicarbonate (keep Mb soluble)

Front 65

what are the street downers:

Back 65

Marijuana
Heroin
Alcohol

Front 66

Heroin

Back 66

"smack, ****": inhibits AC => constipation, pinpoint pupils
(Tx: naloxone, Methadone)

Front 67

Alcohol

Back 67

=> ataxia, euphoria, slurred speech, ⇧GGT, AST>ALT
(Tx: thiamine/glucose.+ BZ)

Front 68

Marijuana

Back 68

"dope, grass, weed, pot": Δ-9 THC => munchies, red eyes, impaired time orientation

Front 69

Isoelectric Point (pi)

Back 69

pH at which there is no net charge (pi= (pK1 + pK2)/2)

Front 70

Zwitterions

Back 70

have a negative carboxy and positive amino end

Front 71

Cathode

Back 71

where cations go, the negative electrode

Front 72

Anode

Back 72

where anions go, the positive electrode

Front 73

Acidic aa

Back 73

Asp, Glu

Front 74

Basic aa

Back 74

Lys, Arg

Front 75

what enzyme cut basic aa?

Back 75

Trypsin cuts basic aa

Front 76

Sulfur aa

Back 76

Cys, Met

Front 77

what enzyme cuts aa that have sulfur in them?

Back 77

β-ME cuts

Front 78

0-Bonds aa?
significance of Tyr?

Back 78

Ser, Thr, Tyr
Tyr makes catecholamines, melanin

Front 79

N-Bonds aa?
significance?

Back 79

Asn, Gln
Acid hydrolysis denatures

Front 80

Branched aa?
significance?

Back 80

Leu, Ile, Val
Maple syrup urine disease

Front 81

what are Aromatic aa?
what enzyme cuts them?

Back 81

Phe, Tyr, Trp
Chymotrypsin cuts "bulky word/ rings"

Front 82

Smallest aa?
significance?

Back 82

Gly
Spinal cord inhibitor

Front 83

NMDA pathway excitatory aa?

Back 83

Asp

Front 84

Kinky (Imino)
significance?

Back 84

Pro
Yellow on Nurhydrin reaction

Front 85

Active sites aa

Back 85

Ser

Front 86

Ketogenic
significance

Back 86

Lys, Leu
Broken down to Acetyl CoA

Front 87

Glucogenic +Ketogenic

Back 87

Phe, Iso, Thr, Trp
(Bulky)
"Mr. PITT never Tyrs"

Front 88

who should avoid Ketogenic diet

Back 88

Diabetes I

Front 89

who should avoid glucogenic diet

Back 89

Diabetes II

Front 90

Reasons for Dialysis:

Back 90

• Symptomatic Uremia
• Symptomatic Acidosis
• Hyperkalemia

Front 91

Disulfide Bonds:

Back 91

"PIGI"
• PRL
• Insulin
• GH
• lnhibin

Front 92

what does Increased GABA levels lead to?

Back 92

bradycardia, lethargy,
constipation, impotence, and memory loss. This means that anything or any disease that increases acidosis, urea, or ammonia will lead to an increase in GABA which will slow everything down.
NH3 + H+ ⇨ NH4+ αKG ⇨ Glu ⇨ GABA

Front 93

Essential FA (must eat 'em):

Back 93

Linolenic
Linoleic ⇨ AA ⇨ PG

Front 94

Essential Amino Acids: you gotta eat 'em:

Back 94

"PVT TIM HALL"
Phe, Val, Trp ⇨5HT, Thr, Ile, Met ⇨Cys, His, Arg, Leu, Lys

Front 95

Newborn screening:

Back 95

"Please Check Before Going Home"
PKY (Guthrie test)
Congenital adrenal hyperplsia
Biotiniase deficiency
Galactosemia
Hypothyroidism

Front 96

Energy Utilization:

Back 96

1) Plasma Glucose: 2-4 hr
2) Liver Glycogen: 24-48 hr
3) Proteolysis for Gluconeogenesis
4) Fats for Lipolysis
5) Ketones for Ketogenesis

Front 97

AA Disorders (AD):

Back 97

Met + ATP ⇨ SAM ⇨ Homocysteine ⇨ Cys + propionylCoA ⇨ MMCoA

Front 98

PKU

Back 98

Phe ⇨ Tyr ⇨ DOPA ⇨ DA ⇨ NE ⇨ Epi
DOPA ⇨T4 and Melanin (albinism)

Front 99

Phenylketonuria:
presentation and test

Back 99

No Phe ⇨ Tyr (via Phe-OHase)
• Mental retardation (can't make DA, NE, Epi)
• Pale, blond, blue eyes (no melanin)
• Musty odor (phenylacetate + phenylpyruvate)
• Nutrasweet sensitivity (Phe)
• Sclerodermatous plaques
• Test: Guthrie test (bacterial inhibition assay)

Front 100

Albinism

Back 100

No Tyr ⇨ Melanin (via Tyrosinase)
• Paleness, predisposed to skin cancer

Front 101

Vitiligo:

Back 101

• Anti-melanocyte AB
• Pale, predisposed to skin cancer
• Ex: Michael Jackson.

Front 102

Alkaptonuria "Ochronosis":

Back 102

• Kids w / osteoarthritis (black tendons), black urine
• Homogentisic acid oxidase deficiency

Front 103

Maple Syrup Urine Disease:

Back 103

"Life is sweet, so LIV it up!"
Defective renal transport of branced aa (Leu, Iso, Val) => aa leak out

Front 104

Homocystenuria: mode of inheritance, pathogenesis

Back 104

Homocysteinuria (AD): No homocysteine ⇨Cys⇨(via cystathione synthase)
>Defective amino acid transport

Front 105

Homocystenuria is caused by?
presentation

Back 105

>Caused by high fat diet: increased Met levels
>Dislocated lens from top "
>Recurrent kidney stones

Front 106

what are the 4 Amino Acids show up in Urine in homocystenuria?

Back 106

Defective amino acid transport "COLA"
• cystine stones⇦ + urine CN Nitroprusside
• ornithine
• Lysine - basic aa
• Arginine - basic aa